Thursday, August 27, 2009

It has happened. Powdery Mildew (PM) has come to the Edible Landscape. Thankfully we have many resistant varieties in the edible landscape, so plants such as petunias and zinnias (which are commonly susceptible) have gone unharmed. The trouble is primarily with the squash. The winter squash and melons have it the worst. Zucchini is next. I also noticed it on the Red Lake currant. The cucumbers look ok so far, as do the yellow summer squash.

Good cultural practices can help prevent an outbreak. These include:

planting resistant varieties (not too helpful if you like to grow heirlooms)

locating plants in a sunny area (minimizing shade)

maintaining good air circulation around the plants to keep humidity low

avoiding excess fertilizing (too much and you'll have so much foliage that air circulation will be reduced)

removing infected material to reduce spread (although once powdery mildew is out there, it seems impossible to stop it)

using drip irrigation, and avoiding excessive irrigation

Many extension bulletins go on to say that regular applications of fungicide may be necessary, starting at the first sign of infection and every 10 days thereafter. This is rarely necessary in the home garden, and should be avoided. PM generally doesn't arrive until late in the season when plants are declining anyway. It is also very season-dependent, so just because you had it this year, doesn't mean you will next year.

There are some organic home remedies and a couple of commercial products out there that I have not personally tried, but may offer prevention and in some cases control of a powdery mildew infection. As one reader found, a mixture of milk and water is often recommended on various gardening websites. One of the few commercial products for organic control of PM is Green Cure, a product developed by a plant pathologist at Cornell University. It is a potassium bicarbonate-based substance, and the manufacturers claim it can be used as a preventative and also will control existing infections. Be sure to do your homework before applying any type of treatment to your plants.

Another round of lettuce. Seeds were sown
in a little bare spot where previous lettuce
had bolted.

It's getting to that time of year when the edible landscape starts to look a little....tired. The former sea of golden calendula is now a sea of developing seed-heads (keeping up with dead-heading seems futile). The cosmos are leaning and looking a little spindly. The dill has completely gone to seed and is beginning to flop over due to its magnificent height. And while I should perhaps have pulled it out weeks ago and put something else in, I love its height and the copper color it has attained. Besides, the void would be tough to fill. So with the help of Erin (my diligent garden assistant) I stake up the thick, woody stalks to allow the dill to enjoy the rest of the season as the garden's loftiest inhabitant.

Some of the annuals, so vigorous throughout the season, have overgrown their allotted space or simply overgrown their ability to hold themselves up any longer. Take for example the borage. Having grown to about 4 feet, with stems almost 2 inches in diameter, these fleshy plants are so heavy that staking has proved useless...they simply take the stakes down with them. So I've been pulling some, mainly to keep them from smothering some of their neighbors like the yellow squash and various peppers. To fill the voids left behind, I moved a few containers with blueberry and mint from their original spots (which were so filled with kale you could barely see the containers anymore), added a little mulch around them and, voila! This tired, overgrown bed now looks fresh again.

Tucking radish seeds into a late-season
empty spot in the edible landscape.

The Edible Landscape is getting a makeover in other areas too! Mustard greens that have bolted were removed, a few woody and dry summer savory plants were pulled, the chervil and cilantro which both have flowered and become ragged were removed...all to make way for the planting of some autumn vegetables. Stop panicking...yes, I said "autumn". But don't be afraid. Late summer is the perfect time to plant some new crops for fall. And it is strangely satisfying to pull out a few of those tired summer plants to make way for something fresh and new. Adding a little compost and preparing a bed for late-season beets, radishes, lettuces, chard and kale has a rejuvenating effect. And it is heartening to know that when the last of the glorious tomatoes have been harvested, there will be something new to look forward to as the days grow cooler. All these plants appreciate the cooler days to come, and their flavors will be sweetened by the crispness of autumn. And since this is an edible landscape, we can be cheered by the thought that these new additions will offer stunning color and texture long after many flowers have begun to fade. Wouldn't you know it, the University of Minnesota Extension Service has a handy guide for planting vegetables for fall harvest. It's not too late to add something new to your edible landscape! If you're having trouble finding seeds locally, here are a few online sources I've had success with.

Wednesday, August 12, 2009

Burgundy okra growing along side zinnias. Look at those
colors! And check out that creamy yellow okra flower!

We often think of okra as a southern staple, and rightly so: this plant thrives in hot weather. But it is possible to successfully grow okra up here in the north, because okra a fairly fast grower (60 days for 'Burgundy'). So it works even in our short growing season. Yields may not be as high as in the steamy south, but the plant alone is worth the effort. We have 'Burgundy' okra in the Edible Landscape, and the plant's deep maroon color is a beautiful contrast against the bright green stems and pastel blooms of the adjacent zinnias. Not only that, the okra flower is a sight to behold. A member of the Malvaceae (mallow) family, its relatives are hibiscus and hollyhock. The five-petaled flowers unfurl to reveal a creamy yellow (or pink) blossom, with a purple center. These flowers are replaced by deep burgundy pods within a few days, which should be picked young (4" long, unlike the one in the photo) for best flavor and texture.

On Saturday August 8, 2009 a group of about 40 Master Gardeners attended a conference session at the Edible Landscape. We talked about the whats and whys of edible landscaping, and (despite the rain) spent some time in the garden exploring a few of the plants one might not often think about using in the landscape, such as kale and chard, as well as others that are more common. Participant groups searched the garden for information cards about their assigned plant which included plant species and family, cultural information, and culinary qualities of the plant. Participants then summarized this information to the rest of the group and offered their ideas on how their assigned plant might be utilized in the landscape. Some of the great ideas included:

strawberries as a ground cover

kale used to add height to the garden and interplanted with a colorful, low, trailing ground cover

chard in mass plantings or as border plants to show off their colorful stems

calendula to add structure and color to the garden

One of the questions that arose during the session is where to find information on good uses for things like kale or mizuna mustard in the kitchen. One easy way to find information is to do a Google search. As an example, try typing in "kale recipes". You'll be amazed at what you find. I always try to find a site with recipes that are rated by users, because it saves me time deciding if the recipe is worth trying. A few of my favorites are Epicurious, MyRecipes, Food Network and Eating Well. There are countless others that are either online magazines or collections of recipes posted by users. It's fun to search and try new things. And don't be afraid to substitute new ingredients in recipes you know and love. For example, if a recipe calls for spinach, try chard or kale from your edible landscape. You may be surprised to find you like it even better than the original! Here's an example that I've adapted from a recipe I found on Epicurious. It's a little out of season for right now (the thought of eating soup today, when it is 89 degrees, isn't so appealing), but you'll get the idea.

Preparation
Cook garlic in 1/4 cup oil in a 3 1/2- to 4 1/2-quart heavy pot over moderately high heat, stirring, until golden, 1 to 2 minutes. Coarsely cut up tomatoes in can with kitchen shears, then add (with juice) to garlic in oil. Stir in broth, beans, ham, and pepper and bring to a boil. Reduce heat and simmer, uncovered, 5 minutes. Stir in greens and cook until wilted, about 3 minutes.
While stew is simmering, preheat broiler. Put bread on a baking sheet and drizzle with remaining 1/2 tablespoon oil. Broil 3 to 4 inches from heat until golden, 1 to 1 1/2 minutes.
Serve stew with toasts or with crusty bread torn into pieces.

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The internet is a great resource for recipes, so don't be afraid to plant things like broccoli raab, mizuna mustard, pak choy, true siberian kale, okra and tomatillos. Not only will they bring delicious new flavors to your table, they look absolutely stunning in the garden! Of course, if you have any recipe ideas, please feel free to share them here by clicking on the "comment" link at the bottom of this post.

Thanks to all the Master Gardeners who attended the Edible Landscape session at the 2009 MN State Master Gardeners Conference. It was a great morning of sharing ideas!